Manuscript Tables and Figures
Raahil Madhok
05 June, 2020
1 Overview
Sample selection protocol:
Stationary trips
Complete checklists (report all species)
Drop duplicates from group trips.
Drop trips with 1 bird
Duration between 5-240 mins
Overall Notes
Results are sensitive to sample selection criteria (num cities, number days pre/post, home, lockdown date)
We select cities first, and then users. This gives us the same users in each pre/post period (in 2020) with the caveat that users mobility is limited to the top X cities.
Quite few people take stationary trips pre-lockdown.
1.1 Birdwatching Activity in All Cities
Summary Stats for 2020 for all users. Number of users is the counts unique user ID’s on a given day.
1.2 Birdwatching Activity in Top 4 Cities
Number of users is the count of unique user ID’s on a given day. Stationary trips are uncommon pre-COVID. 
1.3 Top 20 Cities
Subset of top 20 cities in which users meeting participation constraint are present.
| COUNTY | STATE | POP_DENSITY |
|---|---|---|
| North East Delhi | Delhi | 36155.2258 |
| Central Delhi | Delhi | 27729.5238 |
| East Delhi | Delhi | 27132.4762 |
| Chennai | Tamil Nadu | 26552.7543 |
| Kolkata | West Bengal | 24306.4541 |
| Mumbai Suburban | Maharashtra | 20979.7354 |
| Mumbai | Maharashtra | 19652.2994 |
| West Delhi | Delhi | 19563.4077 |
| South Delhi | Delhi | 11060.4413 |
| South West Delhi | Delhi | 5446.4561 |
| Bangalore | Karnataka | 4381.3985 |
| New Delhi | Delhi | 4057.2571 |
| Haora | West Bengal | 3306.0866 |
| North 24 Parganas | West Bengal | 2444.9880 |
| Faridabad | Haryana | 2442.2848 |
| South 24 Parganas | West Bengal | 819.4740 |
| Hyderabad | Telangana | 706.8919 |
1.4 Pre-Post Lockdown Statistics
This table shows birdwatching activity among users who took at least 2 trips before and after lockdown. Mar 22 trips are dropped.| PREPOST | Num. Trips | Num. Cities | Num. Users | Num. Species |
|---|---|---|---|---|
| Before | 3326 | 179 | 336 | 667 |
| After | 10160 | 135 | 336 | 602 |
| PREPOST | Num. Trips | Num. Cities | Num. Users | Num. Species |
|---|---|---|---|---|
| Before | 662 | 17 | 67 | 205 |
| After | 2014 | 15 | 67 | 215 |
1.5 Trip Statistics
This table shows trip statistics before and after lockdown among users meeting the participation constraint.
| PREPOST | Trip Length | Mean Species Richness | Median Species Richness |
|---|---|---|---|
| Before | 25.05201 | 12.20806 | 10 |
| After | 22.27874 | 12.31033 | 11 |
| PREPOST | Trip Length | Mean Species Richness | Median Species Richness |
|---|---|---|---|
| Before | 22.05589 | 10.43958 | 9 |
| After | 23.33515 | 12.25223 | 11 |
1.6 Marginal Species by city
Marginal species are species observed after lockdown which were not observed before lockdown. To implement: in each city, obtain list of species before and after lockdown observed by users meeting participation cosntraint. Extract species in “after” list not in “before” list.
| COMMON.NAME | SCIENTIFIC.NAME | COUNTY |
|---|---|---|
| falcon sp. | Falco sp. | Kolkata |
| swift sp. | Apodidae sp. | Kolkata |
| white egret sp. | Ardea/Egretta/Bubulcus sp. | Kolkata |
| Little Egret | Egretta garzetta | Kolkata |
| Common Kingfisher | Alcedo atthis | Kolkata |
| Barn Owl | Tyto alba | Kolkata |
| Fulvous-breasted Woodpecker | Dendrocopos macei | Kolkata |
| Asian Openbill | Anastomus oscitans | Kolkata |
| Paddyfield Pipit | Anthus rufulus | Kolkata |
| Gray-headed Swamphen | Porphyrio poliocephalus | Kolkata |
| Scaly-breasted Munia | Lonchura punctulata | Kolkata |
| Rufous Woodpecker | Micropternus brachyurus | Kolkata |
| Zitting Cisticola | Cisticola juncidis | Kolkata |
| Oriental Honey-buzzard | Pernis ptilorhynchus | Kolkata |
| Eurasian Moorhen | Gallinula chloropus | Kolkata |
| Red-breasted Parakeet | Psittacula alexandri | Kolkata |
| Spotted Owlet | Athene brama | South 24 Parganas |
| Taiga Flycatcher | Ficedula albicilla | South 24 Parganas |
| Red-whiskered Bulbul | Pycnonotus jocosus | South 24 Parganas |
| Bengal Bushlark | Mirafra assamica | South 24 Parganas |
| Blyth’s Reed Warbler | Acrocephalus dumetorum | South 24 Parganas |
| Shikra | Accipiter badius | South 24 Parganas |
| Indian Golden Oriole | Oriolus kundoo | South 24 Parganas |
| Barn Owl | Tyto alba | South 24 Parganas |
| Rufous Woodpecker | Micropternus brachyurus | South 24 Parganas |
| Indian White-eye | Zosterops palpebrosus | West Delhi |
| Laughing Dove | Streptopelia senegalensis | West Delhi |
| Rose-ringed Parakeet | Psittacula krameri | West Delhi |
| prinia sp. | Prinia sp. | West Delhi |
| Jungle Babbler | Turdoides striata | West Delhi |
| Black Drongo | Dicrurus macrocercus | West Delhi |
| Yellow-eyed Babbler | Chrysomma sinense | Bangalore |
| Indian Silverbill | Euodice malabarica | Bangalore |
| swift sp. | Apodidae sp. | Bangalore |
| ibis sp. | Threskiornithidae sp. (ibis sp.) | Bangalore |
| Common Hawk-Cuckoo | Hierococcyx varius | Bangalore |
| parakeet sp. | Psittaciformes sp. (parakeet sp.) | Bangalore |
| Greater Spotted Eagle | Clanga clanga | Bangalore |
| Red-rumped Swallow | Cecropis daurica | Bangalore |
| Ashy Woodswallow | Artamus fuscus | Bangalore |
| Pied Kingfisher | Ceryle rudis | Bangalore |
| Eurasian Spoonbill | Platalea leucorodia | Bangalore |
| bird sp. | Aves sp. | Bangalore |
| cormorant sp. | Phalacrocoracidae sp. | Bangalore |
| stork sp. | Ciconiidae sp. | Bangalore |
| Lonchura sp. | Lonchura sp. | Bangalore |
| Oriental Honey-buzzard | Pernis ptilorhynchus | Bangalore |
| Garganey | Spatula querquedula | Bangalore |
| Black-rumped Flameback | Dinopium benghalense | Bangalore |
| White-naped Woodpecker | Chrysocolaptes festivus | Bangalore |
| Blue-throated Flycatcher | Cyornis rubeculoides | Bangalore |
| Blue-faced Malkoha | Phaenicophaeus viridirostris | Bangalore |
| prinia sp. | Prinia sp. | Bangalore |
| flowerpecker sp. | Prionochilus/Dicaeum sp. | Bangalore |
| Red-naped Ibis | Pseudibis papillosa | Bangalore |
| bee-eater sp. | Merops sp. | Bangalore |
| eagle sp. | Accipitridae sp. (eagle sp.) | Bangalore |
| duck sp. | Anatinae sp. | Bangalore |
| Eurasian Coot | Fulica atra | Bangalore |
| Blyth’s Pipit | Anthus godlewskii | Bangalore |
| Black-naped Monarch | Hypothymis azurea | Bangalore |
| Indian Blue Robin | Larvivora brunnea | Bangalore |
| Indian Pitta | Pitta brachyura | Bangalore |
| Black/Ashy Drongo | Dicrurus macrocercus/leucophaeus | Bangalore |
| Yellow Bittern | Ixobrychus sinensis | Bangalore |
| Indian Silverbill | Euodice malabarica | Mumbai |
| Rosy Starling | Pastor roseus | Mumbai |
| Indian Robin | Copsychus fulicatus | Mumbai |
| Jungle Babbler | Turdoides striata | Mumbai |
| Phylloscopus sp. | Phylloscopus sp. | Mumbai |
| Indian Cormorant | Phalacrocorax fuscicollis | Mumbai |
| Asian Openbill | Anastomus oscitans | Mumbai |
| Shikra | Accipiter badius | Mumbai |
| Little Stint | Calidris minuta | Mumbai |
| Brahminy Kite | Haliastur indus | Mumbai |
| wagtail sp. | Motacilla sp. | Mumbai |
| Ashy Woodswallow | Artamus fuscus | North 24 Parganas |
| Lesser Whistling-Duck | Dendrocygna javanica | North 24 Parganas |
| Little Swift | Apus affinis | North 24 Parganas |
| Indian Peafowl | Pavo cristatus | East Delhi |
| White-throated Kingfisher | Halcyon smyrnensis | East Delhi |
| Green Bee-eater | Merops orientalis | East Delhi |
| Rosy Starling | Pastor roseus | East Delhi |
| Striated Babbler | Turdoides earlei | East Delhi |
| Black Redstart | Phoenicurus ochruros | East Delhi |
| Red-whiskered Bulbul | Pycnonotus jocosus | East Delhi |
| White Wagtail | Motacilla alba | East Delhi |
| Bank Myna | Acridotheres ginginianus | East Delhi |
| Great Cormorant | Phalacrocorax carbo | East Delhi |
| passerine sp. | Passeriformes sp. | East Delhi |
| Green Sandpiper | Tringa ochropus | East Delhi |
| Indian Pond-Heron | Ardeola grayii | East Delhi |
| Hume’s Warbler | Phylloscopus humei | East Delhi |
| Greater Coucal | Centropus sinensis | East Delhi |
| Gray-breasted Prinia | Prinia hodgsonii | East Delhi |
| Red-breasted Flycatcher | Ficedula parva | East Delhi |
| Woolly-necked Stork | Ciconia episcopus | East Delhi |
| Red-naped Ibis | Pseudibis papillosa | East Delhi |
| Shikra | Accipiter badius | East Delhi |
| Indian Cormorant | Phalacrocorax fuscicollis | East Delhi |
| Egyptian Vulture | Neophron percnopterus | East Delhi |
| swift sp. | Apodidae sp. | East Delhi |
| Little Swift | Apus affinis | East Delhi |
| Indian Golden Oriole | Oriolus kundoo | East Delhi |
| Gray Heron | Ardea cinerea | East Delhi |
| ibis sp. | Threskiornithidae sp. (ibis sp.) | East Delhi |
| Indian Spotted Eagle | Clanga hastata | East Delhi |
| Purple Heron | Ardea purpurea | East Delhi |
| Indian Spot-billed Duck | Anas poecilorhyncha | East Delhi |
| Little Egret | Egretta garzetta | East Delhi |
| Lesser Whitethroat | Sylvia curruca | East Delhi |
| Indian Golden Oriole | Oriolus kundoo | Mumbai Suburban |
| Laughing Dove | Streptopelia senegalensis | Mumbai Suburban |
| Indian Robin | Copsychus fulicatus | Mumbai Suburban |
| parakeet sp. | Psittaciformes sp. (parakeet sp.) | South Delhi |
| Rosy Starling | Pastor roseus | South Delhi |
| crow sp. | Corvus sp. (crow sp.) | South Delhi |
| Large Gray Babbler | Turdoides malcolmi | South Delhi |
| House Sparrow | Passer domesticus | South Delhi |
| Indian Robin | Copsychus fulicatus | South Delhi |
| Spotted Dove | Streptopelia chinensis | Chennai |
| sunbird sp. | Nectariniidae sp. (sunbird sp.) | Chennai |
| white egret sp. | Ardea/Egretta/Bubulcus sp. | Chennai |
| owl sp. | Strigiformes sp. | Chennai |
| Orange-headed Thrush | Geokichla citrina | Chennai |
| Red-whiskered Bulbul | Pycnonotus jocosus | Chennai |
| Western Yellow Wagtail | Motacilla flava | Chennai |
| Indian Silverbill | Euodice malabarica | Chennai |
| Pied Kingfisher | Ceryle rudis | Chennai |
| House Sparrow | Passer domesticus | Chennai |
| Plain Prinia | Prinia inornata | Chennai |
| Asian Openbill | Anastomus oscitans | Chennai |
| Asian Pied Starling | Gracupica contra | Chennai |
| Ashy Prinia | Prinia socialis | Chennai |
| Black Bittern | Ixobrychus flavicollis | Chennai |
| tern sp. | Sterninae sp. | Chennai |
| swift sp. | Apodidae sp. | Chennai |
| Little Swift | Apus affinis | Chennai |
| Oriental Honey-buzzard | Pernis ptilorhynchus | South West Delhi |
| Little Swift | Apus affinis | South West Delhi |
| old world warbler sp. | Passeriformes sp. (Old World warbler sp.) | South West Delhi |
| Egyptian Vulture | Neophron percnopterus | South West Delhi |
| Indian Golden Oriole | Oriolus kundoo | South West Delhi |
| Long-tailed Shrike | Lanius schach | South West Delhi |
| Common Chiffchaff | Phylloscopus collybita | South West Delhi |
| Short-toed Snake-Eagle | Circaetus gallicus | South West Delhi |
| Gray Heron | Ardea cinerea | South West Delhi |
| Great Cormorant | Phalacrocorax carbo | South West Delhi |
| Blyth’s Reed Warbler | Acrocephalus dumetorum | South West Delhi |
| Brown Rock Chat | Oenanthe fusca | South West Delhi |
| Rose-ringed Parakeet | Psittacula krameri | North East Delhi |
| Brown-headed Barbet | Psilopogon zeylanicus | North East Delhi |
| Asian Koel | Eudynamys scolopaceus | North East Delhi |
| Coppersmith Barbet | Psilopogon haemacephalus | North East Delhi |
| Large Gray Babbler | Turdoides malcolmi | North East Delhi |
| Rock Pigeon | Columba livia | North East Delhi |
| Alexandrine Parakeet | Psittacula eupatria | Faridabad |
| Common Myna | Acridotheres tristis | Faridabad |
| Rock Pigeon | Columba livia | Faridabad |
| Black Kite | Milvus migrans | Faridabad |
| Asian Koel | Eudynamys scolopaceus | Faridabad |
| Asian Pied Starling | Gracupica contra | Faridabad |
| Rose-ringed Parakeet | Psittacula krameri | Faridabad |
| Indian White-eye | Zosterops palpebrosus | Faridabad |
| Laughing Dove | Streptopelia senegalensis | Faridabad |
| Brown-headed Barbet | Psilopogon zeylanicus | Faridabad |
| Coppersmith Barbet | Psilopogon haemacephalus | Faridabad |
| Yellow-footed Green-Pigeon | Treron phoenicopterus | Faridabad |
| Cattle Egret | Bubulcus ibis | Faridabad |
| Eurasian Collared-Dove | Streptopelia decaocto | Faridabad |
| Red-whiskered Bulbul | Pycnonotus jocosus | Faridabad |
| Shikra | Accipiter badius | Faridabad |
| Indian Gray Hornbill | Ocyceros birostris | Faridabad |
| White-throated Kingfisher | Halcyon smyrnensis | Faridabad |
| Blyth’s Reed Warbler | Acrocephalus dumetorum | Faridabad |
| Green Bee-eater | Merops orientalis | Faridabad |
| Large-billed Crow | Corvus macrorhynchos | Hyderabad |
| Tickell’s Blue Flycatcher | Cyornis tickelliae | Hyderabad |
| Cattle Egret | Bubulcus ibis | Hyderabad |
| Thick-billed Flowerpecker | Dicaeum agile | Hyderabad |
| Thick-billed/Pale-billed Flowerpecker | Dicaeum agile/erythrorhynchos | Hyderabad |
| swallow sp. | Hirundinidae sp. | Hyderabad |
| Indian Peafowl | Pavo cristatus | Hyderabad |
| Rufous Treepie | Dendrocitta vagabunda | Hyderabad |
| Indian Robin | Copsychus fulicatus | Hyderabad |
| Dusky Crag-Martin | Ptyonoprogne concolor | Hyderabad |
| Rosy Starling | Pastor roseus | Hyderabad |
| White-browed Wagtail | Motacilla maderaspatensis | Hyderabad |
| Barn Swallow | Hirundo rustica | Hyderabad |
| Indian Pond-Heron | Ardeola grayii | Hyderabad |
| Indian Gray Hornbill | Ocyceros birostris | Hyderabad |
| diurnal raptor sp. | Accipitriformes/Falconiformes sp. | Hyderabad |
| parakeet sp. | Psittaciformes sp. (parakeet sp.) | Hyderabad |
| Glossy Ibis | Plegadis falcinellus | Hyderabad |
| Little Egret | Egretta garzetta | Hyderabad |
| River Tern | Sterna aurantia | Hyderabad |
| Gray-bellied Cuckoo | Cacomantis passerinus | Hyderabad |
| Western Yellow Wagtail | Motacilla flava | Hyderabad |
| Gray Wagtail | Motacilla cinerea | Hyderabad |
| Eurasian Kestrel | Falco tinnunculus | Hyderabad |
| Large-billed Leaf Warbler | Phylloscopus magnirostris | Haora |
| Barn Swallow | Hirundo rustica | Haora |
| Eurasian Collared-Dove | Streptopelia decaocto | Haora |
| Asian Palm-Swift | Cypsiurus balasiensis | Haora |
| White-throated Kingfisher | Halcyon smyrnensis | Haora |
| Jungle Babbler | Turdoides striata | Haora |
| Intermediate Egret | Ardea intermedia | Haora |
| Green-crowned Warbler | Phylloscopus burkii | Haora |
| Blue-throated Flycatcher | Cyornis rubeculoides | Haora |
| Large-billed Crow | Corvus macrorhynchos | Haora |
| Greater Coucal | Centropus sinensis | Haora |
| Cattle Egret | Bubulcus ibis | Haora |
| Asian Brown Flycatcher | Muscicapa dauurica | Haora |
| Rufous Treepie | Dendrocitta vagabunda | Haora |
| Greenish Warbler | Phylloscopus trochiloides | Haora |
2 Event Study
We estimate:
\[ SR_{ijtd} = \sum_{e=-24, e\neq0}^{24} 1(t-LD=e)\beta_{e} + X_{ijdt} + \theta_{i} + \gamma_{t} + \epsilon_{ijtd}\] where \(SR_{ijtd}\) is species richness observed by user i on trip j on date t in district d. Each coefficient \(\beta_{e}\) captures species richness relative to the day of lockdown (LD). In the preferred specification, LD = March 24, 2020 and this date is normalized to zero and omitted so that it describes the reference period. If the timing of lockdown is exogenous to pre-period outcomes, then \(\beta_{e}\) should be zero for all \(e<0\).\(\theta_{i}\) is a user fixed effect and controls for observer bias, experience, and innate ability. Since users primarily remain in the same city before and after lockdown, we do not include a district fixed effect. \(\gamma_{t}\) are a set of temporal controls and include date fixed effects and hour fixed effects. \(X_{ijdt}\) is a vector of controls including trip duration and daily rainfall.
Note:
We start seeing increases in species diversity post-lockdown when we narrow in on urban environments. As we increase number cities, this adds population-sparse places so the effect is dampned.
Larger increases in post-lockdown species diversity as we increase the participation constraint (e.g. 10 days before/after curfew)
2.1 Species Distributions (Bangalore Only)
data: number of times each user sees each species before and after lockdown. interpretation: proportion of user base seeing different frequencies of species.
3 Difference-in-Difference
In this specification, we aim to estimate the difference in species richness per trip before and after lockdown, compared to same difference in 2019. In other words, we subtract the change in the pre-post period of 2019 (the counterfactual) from the 2020 lockdown effect to remove other determinants of species richness that are changing during the window.
To do this, we first select 2020 users with at least 2 trips before and after lockdown. Then we 2019 with the same criteria, using March 24, 2019 as the threshold date. These are different users but share similar characteristics.
Formally, we specify the following standard DID regression:
\[ SR_{ijdt} = \beta_{1} [Treatment_{t} \times Post_{t}] + \beta_{2} [Treatment_{t}] + \beta_{3}[Post_{t}] + X_{ijdt} + \mu_{d} + \gamma_{t} + \epsilon_{ijdt} \]
Where \(Treatment_{t}\) is a dummy for the year 2020 and \(Post_{t}\) is a dummy equal to one for observations after March 24th. \(\beta_{1}\) is the coefficient of interest and describes the change in species richness before and after March 19 in 2020 compared to the same difference in 2019. \(\beta_{2}\) describes the difference in the “before” groups (pre-intervention). \(\beta_{3}\) captures the time trend in the control (2019) group. \(X_{ijdt}\) is a vector of controls including trip duration and rainfall. \(\mu_{d}\) is a set of city fixed effects and \(\gamma_{t}\) is a set of temporal controls including date and hour fixed effects.
| Diff-in-Diff Estimates | ||||
|---|---|---|---|---|
| All Cities, 2 trips | Top 20, 2 trips | Top 20, 5 trips | Top 20, 10 trips | |
| Treat x Post | 0.972*** | 2.738*** | 2.958*** | 2.583*** |
| (0.214) | (0.376) | (0.363) | (0.382) | |
| Duration | 0.131*** | 0.097*** | 0.129*** | 0.127*** |
| (0.002) | (0.004) | (0.006) | (0.006) | |
| Post | -0.664*** | -1.765*** | -1.622*** | -1.176*** |
| (0.233) | (0.410) | (0.404) | (0.431) | |
| Treatment | -4.585* | -12.122*** | -11.747*** | -8.233* |
| (2.464) | (4.346) | (4.390) | (4.686) | |
| Num.Obs. | 19030 | 3723 | 2846 | 2422 |
| R2 | 0.349 | 0.297 | 0.344 | 0.353 |
| Adj.R2 | 0.340 | 0.293 | 0.339 | 0.348 |
| AIC | 123589.0 | 22322.0 | 16363.6 | 13847.6 |
| BIC | 125568.2 | 22490.0 | 16506.5 | 13963.4 |
| Log.Lik. | -61542.516 | -11134.014 | -8157.816 | -6903.795 |
| * p < 0.1, ** p < 0.05, *** p < 0.01 | ||||